1. Field of the Invention
The present invention relates to an image forming apparatus, such as a printer, a facsimile, and a copier.
2. Description of the Related Art
In general, in an image forming apparatus in which an electrostatic photographic process is utilized, a sheet of paper as a recording medium contained in a sheet feeding unit is carried to an image forming unit through a sheet feeding carriage path, and a toner image formed by the image forming unit is transferred. The sheet of paper on which the toner image is transferred is carried to a fixing apparatus, and the toner image on the sheet of paper is fixed. The sheet of paper with the fixed toner image is carried to a sheet discharge tray through a sheet discharge path, or carried to a reversing carriage path. The sheet of paper carried to the reversing carriage path is reversed, and carried to the image forming unit again, thereby the toner image on the back surface of the sheet of paper is transferred.
Japanese Patent No. 4484210 discloses an image forming apparatus which includes a drawer unit. The drawer unit contains the above-described sheet feeding carriage path, the above-described fixing apparatus, the above-described reversing carriage path, and the above-described sheet discharge path. The drawer unit can be drawn out from the image forming apparatus body. When a jam occurs in the carriage path contained in the above-described drawer unit, the drawer unit is drawn out from the apparatus body, thereby easily removing the sheet of paper therefrom.
In the image forming apparatus disclosed in Japanese Patent No. 4484210, when drawing out the drawer unit from the apparatus body, it is drawn out in accordance with the following procedure. First, the front cover is opened to expose the drawer unit. Next, the lock is released by operating a lock lever locking the drawer unit in the apparatus body, to draw out the drawer unit. Accordingly, in the image forming apparatus disclosed in Japanese Patent No. 4484210, it is necessary that the front cover is opened and the lock lever is operated, to draw out the drawer unit. Thus, many operations are required for drawing out the drawer unit, resulting in a problem of decreasing the work efficiency.
The applicant of the present invention has worked the following image forming apparatus under development. That is, it is an image forming apparatus in which a front cover as an outer cover is fixed to a drawer unit, and in which the drawer unit locked in the apparatus body is automatically unlocked using a motor as a driving source.
In the image forming apparatus under development, if a jam occurs in a carriage path of the drawer unit, the drawer unit is automatically unlocked by driving a motor provided in the drawer unit. When a user removes a sheet of paper in the carriage path of the drawer unit, the front cover is drawn out toward the front, thereby drawing out the drawer unit. Accordingly, in the image forming apparatus under development, when the user draws out the drawer unit, only an operation for drawing out the front cover is necessary. Thus, as compared to the image forming apparatus disclosed in Japanese Patent No. 4484210, an easier operation is necessary for drawing out the drawer unit. This results in enhancing the work efficiency for a jam process.
However, in the image forming apparatus under development, the drawer unit is not possibly drawn out from the apparatus body, if the motor unlocking the drawer unit is damaged. As a result, the drawer unit is not possibly exposed, causing another problem that it is very difficult to replace the damaged motor.
Therefore, there is a need to provide an image forming apparatus, in which a drawer unit can be drawn out with an easy operation, and a damaged driving source can easily be replaced even if the drawer unit is not possibly drawn out due to the damaged driving source.